1. Field of the Invention
The invention relates to surgical appliances and more particularly to laryngeal stents for use in a mammal, including a human.
2. Brief Description of the Prior Art
Laryngeal stents are appliances inserted into the larynx of a mammal for support of the larynx structure during a period of healing, for example following surgery. Early laryngeal stents were relatively rigid, solid devices sculpted to mate with anatomical features of the larynx. Sutured in place, the stents were often sources of tissue irritation, causing degrees of trauma, edema and local discomfort. These early stents also blocked the normal airway, requiring the ancillary presence of a tracheotomy. Should the tracheotomy become restricted by mucous or the like, the laryngeal stent blockage could become critical, giving rise to great discomfort and further trauma to the larynx as the stent is moved in response to the mammal's reflex to a lack of air.
An important improvement in the art occurred with development of the Eliachar laryngeal stent (U.S. Pat. No. 4,794,924 issued Jan. 3, 1989). This improved stent provided a relatively rigid, hollow tube to replace the earlier solid body of the stent. A valve at one end of the stent provided air communication through the hollow tube, when high pressure build up below the stent required venting (for example as occurs when the patient coughed). Although the stent body was still relatively rigid, the tube walls were more resilient than a solid stent, permitting some degree of conformation with the larynx anatomy. However, a given device, represented a compromise of desired physical features. For example, if the stent was manufactured with very thin, very flexible hollow bodies, it would exert little pressure on larynx tissues with consequent reductions in irritation. However, this may sacrifice physical support for immobilizing larynx structures. On the other hand, if the hollow body walls are manufactured with greater thickness, the desired flexibility and resilience is sacrificed to achieve the support objective. The surgeon has therefore been faced with a need to select from an inventory of different stents, to satisfy the variety of individual patient needs.
The laryngeal stents of the present invention are a further advance in the art, allowing one to control both surface resilience and support structure provided by the stent. Anchoring of the stent within the larynx is facilitated, without the need for suturing to the patient's tissue. Other advantages associated with the laryngeal stents of the invention will be described hereinafter in relation to particular embodiment stents.